/**
 * Bleach bypass shader [http://en.wikipedia.org/wiki/Bleach_bypass]
 * - based on Nvidia example
 * http://developer.download.nvidia.com/shaderlibrary/webpages/shader_library.html#post_bleach_bypass
 */

var BleachBypassShader = {
  "uniforms": {
    'tDiffuse': {},
    'opacity': {"value": 1.0}
  },
  "vertexShader": [
    'varying vec2 vUv;',
    'void main() {',
    '	vUv = uv;',
    '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',
    '}'
  ].join('\n'),
  "fragmentShader": [
    'uniform float opacity;',
    'uniform sampler2D tDiffuse;',
    'varying vec2 vUv;',
    'void main() {',
    '	vec4 base = texture2D( tDiffuse, vUv );',
    '	vec3 lumCoeff = vec3( 0.25, 0.65, 0.1 );',
    '	float lum = dot( lumCoeff, base.rgb );',
    '	vec3 blend = vec3( lum );',
    '	float L = min( 1.0, max( 0.0, 10.0 * ( lum - 0.45 ) ) );',
    '	vec3 result1 = 2.0 * base.rgb * blend;',
    '	vec3 result2 = 1.0 - 2.0 * ( 1.0 - blend ) * ( 1.0 - base.rgb );',
    '	vec3 newColor = mix( result1, result2, L );',
    '	float A2 = opacity * base.a;',
    '	vec3 mixRGB = A2 * newColor.rgb;',
    '	mixRGB += ( ( 1.0 - A2 ) * base.rgb );',
    '	gl_FragColor = vec4( mixRGB, base.a );',
    '}'
  ].join('\n')
};
